Double-blind, placebo-controlled antibiotic treatment study of small intestinal bacterial overgrowth in children with chronic abdominal pain

J Pediatr Gastroenterol Nutr. 2011 Apr;52(4):382-6. doi: 10.1097/MPG.0b013e3181effa3b.


Background and objectives: Chronic abdominal pain (CAP) in children may be a precursor to irritable bowel syndrome (IBS) in adults. The prevalence of abnormal lactulose breath tests (LBT) suggesting small intestinal bacterial overgrowth (SIBO) has been reported as 91% in children with CAP and 35% in healthy controls. In addition, patients with IBS with SIBO who responded to nonabsorbable antibiotic treatment with normalization of LBT reported 75% global improvement in symptoms. The aim of the study was to test whether treatment with a nonabsorbable antibiotic may reduce symptoms in children with CAP.

Methods: Seventy-five children ages 8 to 18 years with CAP based on Rome II criteria were enrolled. Subjects underwent baseline LBT and completed symptom-based questionnaires. They were then randomized in a 2:1, double-blind fashion to receive a 10-day course of 550 mg of rifaximin or placebo 3 times per day (t.i.d.). LBT and questionnaires were repeated 2 weeks after treatment.

Results: Forty-nine children received rifaximin and 26 received placebo. There were no differences in demographics between groups. Ninety-four percent who received rifaximin and 92% who received placebo had abnormal baseline LBT, suggesting SIBO (not significant [NS]). There was no significant difference in symptom improvement between groups; however, only 20% of children treated with rifaximin achieved a normalized repeat LBT, demonstrating successful treatment of SIBO.

Conclusions: Similar to adults with IBS, the prevalence of abnormal LBT suggesting SIBO in children with CAP is high; however, treatment with 10 days of rifaximin has low efficacy in normalizing LBT in this group. Additional studies are needed to determine whether a treatment approach with higher efficacy would lead to improvement in children with CAP.

Trial registration: NCT00619970.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abdominal Pain / etiology
  • Abdominal Pain / prevention & control*
  • Adolescent
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / therapeutic use*
  • Breath Tests
  • Child
  • Chronic Disease
  • Double-Blind Method
  • Dyspepsia / etiology
  • Dyspepsia / prevention & control
  • Enteritis / drug therapy*
  • Enteritis / microbiology*
  • Enteritis / physiopathology
  • Female
  • Fermentation / drug effects
  • Gastrointestinal Agents / chemistry
  • Gastrointestinal Agents / therapeutic use*
  • Humans
  • Irritable Bowel Syndrome / drug therapy
  • Irritable Bowel Syndrome / microbiology
  • Irritable Bowel Syndrome / physiopathology
  • Lactulose / metabolism
  • Male
  • Migraine Disorders / drug therapy
  • Migraine Disorders / microbiology
  • Migraine Disorders / physiopathology
  • Rifamycins / chemistry
  • Rifamycins / therapeutic use*
  • Rifaximin
  • Severity of Illness Index
  • Surveys and Questionnaires


  • Anti-Bacterial Agents
  • Gastrointestinal Agents
  • Rifamycins
  • Lactulose
  • Rifaximin

Associated data